I used to own the e2c's. I picked them up because they looked the burliest with super thick cables and behind the ear insertion. I don't really remember how they sounded like anymore. They were quite comfortable.
They lasted about a year and a 1/2 of abuse.
The ONE thing annoying about IEM's is the cable rub or when your eating / chewing gum. You hear the sound amplified in your head.

I've also breifly owned the Er-4p's. The sound was real neutral which is what tons of audiophiles are looking for, but the sound just isn't for me. And inserting the white tips wasn't a pleasant experience for my ears.

If I was to buy again, I'd probably try for the Ultimate Ears Super.Fi range. They seems pretty awesome and I really do like the behind ear design as I think it looks a little bit more discreet. I do believe the E2c's are quite a bit older and discontinued? I'm sure they're way cheap by now though. I'd def. recommend them for your first IEM.

I won't ever go back to ear buds. I can't stand the ambient noise that you have if you take the TTC or walk down the street.

As for hearing damage, I don't think any of these setups would be particularly bad for you. no idea.
I find I use a much lower vol. setting using in ear headphones, but thats simply because all ambient noise is blocked off.